Don’t know if it applies to postwar ST, but I have a W.&C. Scott that was the last Premier built with SST, and it is the Lard patent trigger design as used by Westley Richards with the sliding selector beside the trigger. The gun was built in 1924, and the trigger has operated perfectly in the 30+ years I have owned it.I seem to remember that Scott and W&S used several different designs before settling on the WR design.I do know that you rarely find a prewar W&S or Scott gun with a factory SST. Sandlapper